Parity Violation in Nuclei

Abstract

Nuclear parity violation1 provides a window on a part of the hadronic weak interaction which is otherwise invisible. The idea of a universal weak current which acts in hadrons as well as leptons is of course central to all modern theories of the electroweak force but it is one which does not readily admit testing. We have some experimental knowledge of ΔS=1 and ΔC=1 non-1eptonic weak processes, and there is little cause for satisfaction in our understanding of those processes. The only immediate prospect for probing the ΔS=0 interaction is nuclear parity violation, and in the early days it was hoped that much of a fundamental nature might be learned. This optimism soon yielded to gloom when the cluttered nature of the nuclear workshop became apparent. Now, following substantial efforts both by theorists and experimentalists there is a renewed, more conservative optimism that nuclear parity violation (PV) can be understood at a level which tests our ability to calculate hadronic interactions, although it is not likely to influence the development of the underlying theories of the weak interaction.